Everyone is scared at first, then when you see all those green and tan things come out, you'll want to do it again.
I have no idea on the apple juice cleanse. I"ve never used it. I use the dr. clarke liver cleanse. check it out: //www.curezone.org/clark/liver.asp
She likes you to do a parasite cleanse first. She claims you can get sick if you have parasites. I've heard lots of great posters say they never did the parasite cleanse and was just fine.
Metamucel does have psyllium in its, but also alot of sugar. I guess if you've already bought, no need to waste. But the psyllium husks are actually better, and cheaper. The prune juice does not do the same thing.
that's what I know about it, I'm sure you'll get a lot of great advise from other posters.